From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A6733C433DB for ; Mon, 1 Feb 2021 11:52:17 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id F257964E50 for ; Mon, 1 Feb 2021 11:52:16 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F257964E50 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 65B686B0070; Mon, 1 Feb 2021 06:52:16 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 632A86B0071; Mon, 1 Feb 2021 06:52:16 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 56ECC6B0072; Mon, 1 Feb 2021 06:52:16 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0214.hostedemail.com [216.40.44.214]) by kanga.kvack.org (Postfix) with ESMTP id 3CCCB6B0070 for ; Mon, 1 Feb 2021 06:52:16 -0500 (EST) Received: from smtpin21.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 055243631 for ; Mon, 1 Feb 2021 11:52:16 +0000 (UTC) X-FDA: 77769535872.21.word57_2503a81275c2 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin21.hostedemail.com (Postfix) with ESMTP id D8731180442C2 for ; Mon, 1 Feb 2021 11:52:15 +0000 (UTC) X-HE-Tag: word57_2503a81275c2 X-Filterd-Recvd-Size: 3020 Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by imf47.hostedemail.com (Postfix) with ESMTP for ; Mon, 1 Feb 2021 11:52:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=DFvEMuSmJTMwKrx37KZALAZlQNbzmwOQTAjJ5KIsmrw=; b=w8cvjP/EhS0PSzIPxW+VuBQ9mb TZNQ7dWwgSY6NA0ZJzbMQK6Ku1B2KLt6pqyzZ16Bw1txT58zsTw7Ni3J459la9y5DYgKtNxTVmjyo YUgjsCd7fg6FJ67kJFf80vej3f4ZFRlLieWTI74UD6BVEXKpeGP1XG03NP6MH1MCL+ilraOrakuJl x1dNXJMRx+BR604fYQUQJfEZ1Q84nXFh7f+XKp3wdr2ExO7Tw9AQ36LdJ0z0Wxs+ovIQ5UtmUMquN +jbZ74Xwlo+ObX9Ain6ZPLDiMmMS94XtxKFzz2oC8cueQNZw1+LgT9gWroaPexBgFc9m9QARKLmR3 AV0epSdQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1l6XkX-00035y-Bm; Mon, 01 Feb 2021 11:52:09 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id AE3CA3011FE; Mon, 1 Feb 2021 12:52:07 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 98E9121A2F1E2; Mon, 1 Feb 2021 12:52:07 +0100 (CET) Date: Mon, 1 Feb 2021 12:52:07 +0100 From: Peter Zijlstra To: Nadav Amit Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Nadav Amit , Andrea Arcangeli , Andrew Morton , Andy Lutomirski , Dave Hansen , Thomas Gleixner , Will Deacon , Yu Zhao , Nick Piggin , x86@kernel.org Subject: Re: [RFC 08/20] mm: store completed TLB generation Message-ID: References: <20210131001132.3368247-1-namit@vmware.com> <20210131001132.3368247-9-namit@vmware.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210131001132.3368247-9-namit@vmware.com> X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Sat, Jan 30, 2021 at 04:11:20PM -0800, Nadav Amit wrote: > +static inline void tlb_update_generation(atomic64_t *gen, u64 new_gen) > +{ > + u64 cur_gen = atomic64_read(gen); > + > + while (cur_gen < new_gen) { > + u64 old_gen = atomic64_cmpxchg(gen, cur_gen, new_gen); > + > + /* Check if we succeeded in the cmpxchg */ > + if (likely(cur_gen == old_gen)) > + break; > + > + cur_gen = old_gen; > + }; > +} u64 cur_gen = atomic64_read(gen); while (cur_gen < new_gen && !atomic64_try_cmpxchg(gen, &cur_gen, new_gen)) ;